This edition's guest columnists are writing on topics such as mastering difficult music, viral lines and ear training. We've got six contributed articles altogether - five written by past contributing columnists, and one by a new contributor.

Mike Campese returns with a topical column entitled "Quarantine Lines". Joining us for the first time is Alex Bruce with his article "Intonation: Its Importance And How To Spot Problems". Finally, prolific columnist and guitarist Tommaso Zillio contributes another quadruple shot of columnar expresso: "How To Manage A Difficult Piece Of Music On Guitar", "Ascending And Descending Melodic Minor Scales", "The Simplest Ear Training Exercise For Guitarists" and "The Simplest Ear Training Exercise For Guitarists".

Also, please reread and enjoy a classic column from the Guitar Nine archives, Dan McAvinchey's "The Role of Inspiration".

Our retrospective series is entitled "Guitar Nine's Attic", which in April/May takes a look back at nine of the funnest and even funniest reviews from the Guitar Nine's "The Undiscovered" column feature, which ran from 1996 to 2007.

For nearly 24 years we've offered a free listing on the Home Studio Registry. Join the Registry to meet and hook up with other Home Studio owners like yourself to discuss gear, techniques, maintenance or production.